The prostate gland, a key part of the male reproductive system, is linked closely with the urinary system. It is a small gland that secretes much of the liquid portion of the semen, the milky fluid that transports sperm through the penis when a man ejaculates. The prostate is located just beneath the bladder. It encircles, like a donut, a section of the urethra, which is the tube that carries urine from the bladder out through the penis. During ejaculation, semen is secreted by the prostate through small pores in the urethra's walls.
Benign Prostatic Hyperplasia (BPH) is an enlarged prostate. Benign means noncancerous and hyperplasia means excessive growth of tissue. BPH is the result of small noncancerous growths inside the prostate. It is not known what causes these growths, but they may be related to hormone changes that occur with aging. By age 60, more than half of all American men have microscopic signs of BPH, and by age 70, more than 40 percent have enlargement that can be felt on physical examination. The prostate normally starts out about the size of a walnut. By the time a man is age 40, the prostate may already have growth to the size of an apricot. By age 60, it may be as big as a lemon.
BPH, which does not affect sexual function, is nonetheless troublesome. As the prostate enlarges, it presses against the bladder and the urethra, blocking urine flow. A patient with BPH may find it difficult to initiate a urine stream or to maintain more than a dribble. He may also need to urinate frequently, or he may have a sudden, powerful urge to urinate. Many patients suffer from nocturia (i.e., they awaken several times a night to void); others suffer from urgency and frequency (e.g., an annoying feeling that the bladder is never completely empty).
Straining to empty the bladder can make matters worse—the bladder stretches, the bladder wall thickens and loses its elasticity and the bladder muscles become less efficient. The pool of urine that collects in the bladder can foster urinary tract infections, and trying to force a urine stream can produce back pressure that eventually damages the kidneys (a condition known as hydronephrosis).
BPH can lead to other problems. For Instance, a completely blocked urethra is an emergency requiring immediate catheterization (a procedure where a tube called a catheter is Inserted through the penis into the bladder to allow urine to escape). Other serious potential complications of BPH include bladder stones and bleeding.
About half of the men with BPH develop symptoms serious enough to warrant treatment. BPH cannot be cured, but in many cases, its symptoms are relieved by surgery or by drugs.
BPH Surgery
The popularity of prostate surgery has diminished since drug therapy became available: a total of 250,000 procedures were performed in 1996, down from 400,000 in 1988. Despite this, operations for BPH remain the most common surgery performed on American men. Several types of surgery can relieve the symptoms of an enlarged prostate.
Transurethral Resection of the Prostate (TURP): This procedure accounts for more than 90 percent of all BPH surgeries. TURP relieves symptoms quickly, typically doubling the urinary flow within weeks. This procedure typically proceeds as follows: The patient is numbed from the waist down with an anesthetic injection known as a spinal block. The surgeon then inserts a slim fiberscopic tube through the penis and up the urethra as far as the prostate. Using either a tiny blade or an electric loop, the surgeon pares away the urethra's lining and bits of excess prostate tissue. Gradually, the passageway is expanded.
The TURP procedure ordinarily does not pose the two main dangers generally linked to prostate surgery: incontinence (loss of urinary control) and problems with sexual function, especially sexual impotence (the inability to have an erection). About five percent of men become partially incontinent after the TURP procedure. In addition, some men develop scarring in the urethra, which can block urination. As many as 10 percent will need repeat surgery because prostate tissue grows back.
About five percent of men become impotent after the TURP procedure. But TURP does not usually affect a man's ability to have an erection or orgasm, since the nerves that control erection lie outside the prostate and are not touched by the operation. A more common side effect is a dry or retrograde ejaculation. The result is that semen spurts backward in to the bladder rather than through the penis. Men who experience this side effect still have the sensation of an orgasm but are unable to father children.
Transurethral Incision of the Prostate (TUIP): This procedure Is used in small prostate glands of 30 grams or less and is used far less frequently than TURP. Like TURP, TUIP is performed by passing an instrument through the penis to reach the prostate. The difference is that a doctor makes only one or two small cuts to relieve pressure in the prostate rather than trimming away tissue. Like TURP, the procedure considerably increases the urine flow. TUIP is an outpatient procedure with a low risk of side effects. Because of that, the United States Public Health Service Clinical Practice Guidelines recommend that this technique be used more often.
Transurethral Needle Ablation (TUNA): This technique, which can be done with a local anesthetic on an outpatient basis, uses radio frequency delivered through needles to kill excess prostate tissue. A catheter that deploys the needles toward the obstructing prostate tissue is inserted into the urethra before the procedure begins. Some clinical studies have reported that TUNA improves the urine flow with minimal side effects when compared with other procedures.
Open Prostatectomy: In this procedure, a surgeon makes an incision to reach the prostate, instead of inserting an instrument through the urethra. Open prostatectomy may involve either a radical or a partial procedure. A radical prostatectomy, which removes the whole prostate, is a treatment used for prostate cancer. The incision is made through either the lower abdomen or the perineum. Partial prostatectomy, which leaves the posterior portion of the prostate intact, is used to treat BPH. The incision for a partial prostatectomy is again made through either the lower abdomen or the perineum. Partial prostatectomy once was the sole recourse for an enlarged prostate. Today it is used only on extremely large prostates, which represent about five percent of all cases.
BPH Drug Therapy
Although regarded as less effective than surgery, drugs are also less invasive and usually free of major side effects. Currently two major classes of drugs are used for the treatment of BPH: alpha-adrenergic blockers and finasteride.
Alpha-adrenergic blockers were originally used for the treatment of high blood pressure, as they lead to relaxation of the smooth muscle in blood vessel walls. In BPH, they relax the muscular portion of the prostate and the bladder neck. This allows urine to flow more freely. In the average patient, these drugs increase the rate of urine flow and reduce symptoms, often within days. Side effects include dizziness, fatigue and headache.
Finasteride shrinks the prostate by blocking an enzyme that converts the male hormone testosterone into a more potent, growth-stimulating form. Some, but not all, studies show that taking finasteride for at least six months can increase urinary flow rate and reduce symptoms. It seems to work best for men who have greatly enlarged prostates. In a small percentage of men, the drug can affect sexual activity: decreasing a man's interest in sex, diminishing his ability to have an erection, and causing problems with ejaculation. It sometimes also causes tenderness or swelling of the breasts. It may cause a drop in PSA levels. (PSA is typically elevated in prostate cancer, and finasteride is used in the treatment of prostate cancer.) Stopping the drug typically reverses these side effects.
Other BPH Treatments
Researchers are working to develop BPH treatments that are more effective and less traumatic, with fewer side effects. These include using laser surgery, high amplitude electric currents, and microwaves. Some surgeons have also tried to enlarge the urethra by inserting a balloon into it and inflating it with fluid. Other surgeons have tried inserting a stent into the urethra to hold it open. Brachytherapy, in which “seeds” emitting low-level radiation are implanted in the prostate to kill the surrounding tissue, may also be used to shrink the volume of the prostate, but this treatment is typically reserved for prostate cancer. Transurethral electrovaporization of the prostate has been investigated for treatment of BPH. Electrovaporization is similar to traditional electrocautery; however, electrovaporization requires increased power.
Drawbacks of available BPH treatments include significant side effects, discomfort, inconvenience, and/or complex, risky, expensive surgical procedures, which may be confined to use in patients with severe symptoms and the capacity to finance the surgery. What is needed is an effective treatment for BPH that is minimally invasive, and provides relief without major side effects.